Friction set for railway braking system

ABSTRACT

Disclosed is a friction set for a railway disk brake system for railway rolling stock including: a shoe holder including a receiving slideway; a friction shoe including a brake pad and a profiled shape configured for being slid into the receiving slideway, where the friction shoe includes a pneumatic conduit connecting a first space delimited by a first surface of the friction shoe to a second space delimited by a second opposite surface the friction shoe; a through hole arranged in the shoe holder and laid out so as to be facing the pneumatic conduit; and a pneumatic connector mounted on the shoe holder, pneumatically connected with the through hole, extending away from the friction shoe and rotationally mobile relative to the shoe holder, around an axis perpendicular to a main plane of the shoe holder.

FIELD OF THE INVENTION

The present invention relates to railway rolling stock. Morespecifically, the invention relates to braking of railway rolling stockand in particular the friction couples for braking systems for railwayrolling stock. It will be noted that according to the invention, anyobject configured for rolling on rails is within the scope of theinvention. Thus, the present invention applies for example equally wellto trains, tramways and metropolitan light rail.

DESCRIPTION OF RELATED ART

Railway rolling stock, such as a locomotive, coach or wagon, usuallycomprises a braking system. Disk brakes solutions are one among manypossible solutions for braking. Thus, the braking system generallycomprises a disk secured to a wheel or an axle of the railway rollingstock. The braking system further comprises a friction couple whichcomprises a shoe holder which supports a friction shoe. The frictionshoe usually comprises means for attachment to the shoe holder and abrake pad. When the driver actuates the braking system, the brake pad ofthe friction shoe comes into contact with the disk to exert a brakingforce on the disk. Thus, by friction, the friction shoe brakes the disksecured to the wheel or the axle. Generally, the railway rolling stockcomprises two friction couples, arranged on either side of the disk soas to pinch, or in other words sandwich the disk, in order to compressit from both sides.

The brake pad of the friction shoe usually comprises a metal material,such as cast-iron, a frittered material or a composite material. Thus,when the brake pad of the friction shoe rubs against the disk, particlesof material coming from the brake pad are released into the ambientatmosphere around the friction couple. Thus, the braking system releasesatmospheric pollution in the form of more or less fine particles.

It is therefore sought to capture the particles of material releasedduring braking, in particular by providing a blower or aspirationdevice, supplied by a pump, near a zone of release of particles comingfrom the brake pad of the friction shoe.

However, these devices operate in an open space. In fact, the zone ofrelease of particles coming from braking, specifically the brake pad, isnot confined. This is why, the yield or effectiveness of the blower oraspiration device is relatively low. Further, it is difficult toincorporate these devices in the architecture of the railway rollingstock.

SUBJECT MATTER OF THE INVENTION

The goal of the invention is to provide a friction couple with which tomore effectively capture the particles released by the brake pad and thefriction shoe during the braking cycle and which is easily incorporatedin the architecture of the railway rolling stock.

BRIEF SUMMARY OF THE INVENTION

To do this, according to the invention, a friction couple for a railwaydisk brake system for railway rolling stock with one or two directionsof movement is provided where said friction couple is characterized inthat it comprises:

-   -   a shoe holder comprising a receiving slideway;    -   a friction shoe comprising a brake pad and a profiled shape        configured for being slid into the receiving slideway, where the        friction shoe comprises a pneumatic conduit connecting a first        space delimited by a first surface of the friction shoe to a        second space delimited by a second opposite surface the friction        shoe;    -   at least one through hole arranged in the shoe holder and laid        out so as to be facing the pneumatic conduit; and        A pneumatic connector mounted on the shoe holder, pneumatically        connected with the through hole and extending away from the        friction shoe and rotationally mobile relative to the shoe        holder, around an axis normal to a main plane of the shoe        holder.

Thus, the particles released during braking can reach the pneumaticconduit of the friction shoe, and then the through hole arranged in theshoe holder. Next, they reach the pneumatic connector. Thus, byconnecting the pneumatic connector, for example by means of a hose, to asystem for recovery of braking particles, it is possible to connectthese two. Further, since the pneumatic connector is rotationally mobilearound the axis normal to the main plane of the shoe holder, it ispossible to easily arrange it within the railway rolling stock.

Further, in various embodiments of the invention, use can also be madeof one and/or another of the following provisions:

-   -   the profiled shape is a dovetail;    -   the friction couple comprises a hose pneumatically connected        with the pneumatic connector and extending away from the        friction shoe;    -   the friction couple comprises a pump connected, directly or        indirectly, to the hose and configured for creating reduced        pressure in the through hole;    -   the receiving slideway of the shoe holder is blind, specifically        with one closed end and one open end forming an opening for the        extraction and insertion of the friction shoe, where the        friction set further comprises a removable member for locking        the friction shoe in the receiving slideway;    -   the friction shoe comprises a first member and a second member        configured for being slid in the receiving slideway until        contact of each other in an area of butting of the first and        second members while leaving a passage therebetween so as to        form the pneumatic conduit;    -   the first and second members each form one half of the friction        shoe;    -   the friction shoe can also be single piece;    -   the first and second members are juxtaposed in a direction        tangential to a breaking disk of the railway rolling stock;    -   the passage left at the interface of the first and second        members is arranged in an intermediate part of the butting zone;    -   the butting zone is substantially defined as a butting plane,        the first and second members have similar lengths in a        longitudinal direction of the shoe holder, and the through hole        has a center defining an axis separated from the butting plane        by at least 5 mm or coincident with the butting plane;    -   the friction set comprises a pneumatic junction ring laid out in        the pneumatic conduit forming a pneumatic guide between the        through hole of the shoe holder and the pneumatic conduit;    -   the pneumatic junction ring comprises a flange resting on a        bottom of the receiving slideway and a cylindrical portion;    -   the cylindrical portion has a height equivalent to a height of        the dovetail profiled shape.

According to the invention, a railway disk brake system can finally beprovided for railway rolling stock with two directions of movementcomprising a disk secured to an axle or a wheel and two friction couplesas previously described and arranged on either side of the disk.

Also according to the invention, a friction couple for a railway diskbrake system for railway rolling stock with one or two directions ofmovement is provided where said friction couple is characterized in thatit comprises:

-   -   a shoe holder comprising a receiving slideway;    -   a friction shoe comprising a brake pad and a profiled shape        configured for being slid into the receiving slideway, where the        friction shoe comprises a pneumatic conduit connecting a first        space delimited by a first surface of the friction shoe to a        second space delimited by a second opposite surface the friction        shoe;    -   at least one through hole arranged in the shoe holder and laid        out so as to be facing the pneumatic conduit; and    -   a pneumatic junction ring laid out in the pneumatic conduit        forming a pneumatic guide between the through hole of the shoe        holder and the pneumatic conduit of the friction shoe.

Thus, the friction shoe comprises a pneumatic conduit which forms, withthe through hole arranged in the shoe holder, a pneumatic circuit withwhich to aspirate the particles released, by the brake pad of thefriction shoe, during braking. Further, the pneumatic junction ringserves to guide the particles coming from braking from the pneumaticconduit of the friction shoe to the through hole of the shoe holder. Thepneumatic junction ring therefore serves to limit possible leaks out ofthe pneumatic circuit. In particular, the junction ring serves to limitthe quantity of particles coming from braking which slide in aninterstice located between the friction shoe and the shoe holder. Thefriction set according to the invention therefore serves to aspirate alarger quantity of particles coming from braking for the same aspirationforce. It is therefore more effective. The friction couple according tothe invention therefore serves to simply lay out a pneumatic circuit forremoving the particles from braking.

Further, in various embodiments of the invention, use can also be madeof one and/or another of the following provisions:

-   -   the profiled shape is a dovetail;    -   the pneumatic junction ring comprises a flange resting on a        bottom of the receiving slideway and a portion which preferably        has a conical shape; with this arrangement the pneumatic guide        can be shaped simply;    -   more generally it will be noted that the portion can have any        type of shape and can in particular have an arbitrary shape;    -   the conical portion is cylindrical;    -   the conical portion has a height equivalent to a height of the        profiled shape; with this configuration, the particles coming        from braking can be effectively guided from the pneumatic        conduit of the friction shoe towards the through hole of the        shoe holder;    -   the receiving slideway of the shoe holder is blind, specifically        with one closed end and one open end forming an opening for the        extraction and insertion of the friction shoe, where the        friction couple further comprises a removable member for locking        the friction shoe in the receiving slideway; thus, the friction        shoe can be easily replaced if necessary; the maintenance of the        friction couple is therefore easier;    -   the friction shoe is shaped by a first member and a second        member configured for being slid in the receiving slideway until        contact of each other in an area of butting of the first and        second members while leaving a passage therebetween so as to        form the pneumatic conduit;    -   the first and second members each form one half of the friction        shoe; the passage left at the interface of the two friction        shoes is formed in a central part of the zone of release of        particles released during braking; the aspiration of the        particles released during braking is therefore done in the same        way regardless of the travel direction of the railway rolling        stock; the pneumatic behavior for removal of the particles        released during braking is consequently simpler to model;    -   the first and second members are juxtaposed in a direction        tangential to a braking disk of the railway rolling stock;    -   the passage left at the interface of the first and second        members is arranged in an intermediate part of the butting zone;        it involves a simple fitting;    -   the butting zone is substantially defined as a butting plane;        the first and second members have similar lengths in a        longitudinal direction of the shoe holder, and the through hole        has a center defining an axis separated from the butting plane        by less than 5 mm or coincident with the butting plane; the        aeraulic behavior of the friction couple is therefore symmetric,        which is advantageous since the railway rolling stock has two        directions of motion;    -   the friction couple comprises a pneumatic connector mounted on        the shoe holder, pneumatically connected with the through hole        and extending away from the friction shoe; the pneumatic        connector serves to direct the particles coming from the        pneumatic circuit formed by the conduit of the friction shoe and        the through hole arranged in the shoe holder to a collection        member which has a filter;    -   the pneumatic connector is rotationally mobile relative to the        shoe holder, around an axis normal to a main plane of the shoe        holder; the friction set can therefore be easily incorporated in        a braking system of the railway rolling stock; further, this        mounting tolerates relative movements substantial amplitude;    -   the friction couple comprises a hose pneumatically connected        with the through hole and extending away from the friction shoe;    -   the friction couple comprises a pump connected, directly or not,        to the hose and configured for creating reduced pressure in the        through hole; the friction couple therefore serves to aspirate        the particles coming from braking, through the pneumatic circuit        formed by the pneumatic conduit of the friction shoe and the        through hole arranged in the shoe holder.

According to the invention, a railway disk brake system can also beprovided for railway rolling stock with two directions of movementcomprising a disk secured to an axle or a wheel and two friction sets aspreviously described and arranged on either side of the disk.

It will further be noted that features of the friction couple comprisingthe junction ring and the friction couple comprising the pneumaticconnector can of course be combined.

BRIEF DESCRIPTION OF THE DRAWINGS

As a nonlimiting example, four embodiments of the invention are nowgoing to be described with the help of the following figures:

FIG. 1 is a perspective view of a railway disk brake system according tothe invention.

FIG. 2 is a perspective view of two friction couples according to theinvention;

FIG. 3 is a section view of the friction couple along a plane normal toa longitudinal axis of the friction shoe;

FIG. 4 is a top view of the friction set;

FIG. 5 is an exploded top view of the friction couple;

FIG. 6 is a perspective view of a pneumatic junction ring according tothe invention.

FIG. 7 is a section view of a friction couple, according to a secondembodiment of the invention, along a plane normal to a longitudinal axisof a friction shoe;

FIG. 8 is a top view of the friction couple, according to this secondembodiment;

FIG. 9 is a section view of a friction shoe of the friction coupleaccording to the second embodiment along a plane normal to alongitudinal axis of the friction shoe;

FIG. 10 is a section view of a friction couple, according to a thirdembodiment of the invention, along a plane normal to a longitudinal axisof a friction shoe; and

FIG. 11 is a top view of a friction couple according to a fourthembodiment of the invention.

DETAILED DESCRIPTION OF FOUR EMBODIMENTS OF THE INVENTION

FIG. 1 shows a portion of railway rolling stock 10 comprising a railwaydisk brake system 12 according to the invention. In this embodiment, therailway rolling stock 10 is a train. It will just the same be noted thatthe invention can be implemented in any type of railway rolling stock10. It can therefore be metropolitan light rail or even a tramway.Similarly, the railway rolling stock 10 can be a locomotive or coach.

The railway rolling stock 10 comprises an axle 14 which comprises a mainaxis A1, a disk DK and a wheel 18. The wheel 18 is arranged on a rail 20relative to which it can move by rotation around the axis A1. The axle14, the disk DK and the wheel 18 are secured such that the axle 14 isable to transmit a rotational movement, around the main axis A1, to thedisk DK and to the wheel 18. The railway rolling stock 10 has twodirections of movement. The wheel 18 can therefore move on the rail 20in two opposite directions relative to each other (see S1, S2 on FIG.2).

Further, the railway disk brake system 12 is able to exert pressure onthe disk DK and to do so in order to brake the rotation of the wheel 18around the main axis A1 and therefore consequently brake a movement ofthe railway rolling stock 10 on the rails 20. To do this, the railwaydisk brake system 12 comprises two friction couples 16 arranged oneither side of the disk DK. These two friction couples 16 can beactuated by a hydraulic or pneumatic actuator so as to exert a symmetricbraking force on the disk DK. FIG. 2 in particular shows the dispositionof the two friction couples 16 on either side of the disk DK shown indash-dot lines.

Thus, as shown in FIGS. 2 to 4 in particular, each friction couple 16 ofthe railway disk brake system 12 has a longitudinal axis Z2 shown inFIG. 1, which is coincident with a tangential direction T of the diskDK, and comprises a shoe holder 3 which supports a friction shoe 22. Thefriction shoe 22 is intended to enter into direct contact with the diskDK.

Further, as shown in FIGS. 3 and 4, each friction assembly 16 comprisesa transverse axis X and an axis called vertical Y, where Y is normal tothe friction plane (Y is normal to the friction plane).

The shoe holder 3 comprises, at the upper longitudinal end thereof asseen in FIG. 2, means for attachment 24 to a body of the railway rollingstock 10. These attachment means 24 are in the form of two throughholes, arranged across from each other, thus forming a respective axisX1, X2 for receiving a complementary attachment means borne by the bodyof the railway rolling stock 10. The axes X1, X2 are normal to the axisA1 and the axis Z2. The axes X1, X2 are substantially parallel to thedirection of movement of the railway rolling stock on the rails in theexample shown.

Further, the shoe holder 3 comprises a receiving slideway 4 whichextends longitudinally the length of the shoe holder 3 and which servesto receive the friction shoe 22. As noted in FIG. 5, the receivingslideway 4 is blind. That way, it comprises one closed end 41 and oneopen end 40. The function of this open end 40 is to form an opening forextraction and insertion of the friction shoe 22. In order to positionthe friction shoe 22 in the receiving slideway 4, the shoe holder 3further comprises a movable locking member 19 which takes the shape of aslender member 19 and which is substantially normal to the receivingslideway 4 so as to obstruct the open end 40 of the receiving slideway4. The movable locking member 19 can be secured to the shoe holder 3 totrap the friction shoe 22 in the receiving slideway 4. The movablelocking member 19 can be seen as a robust pin one of the branches ofwhich comes to be housed in a complementary recessed groove arranged inthe shoe holder 3.

Additionally, the shoe holder 3 comprises a through hole 38 arrangedsubstantially in the center of the receiving slideway 4. The throughhole 38 has a center which defines a main axis A8 parallel to thevertical axis Y of the friction couple 16. This main axis A8 is furthernormal to a main plane XY of the shoe holder 3. This axis is also normalto a main plane of the through hole 38.

As can be seen in FIG. 3, the friction shoe 22 comprises a brake pad 7whose function is to come into contact with the disk DK. Thus, thefriction shoe comprises a first surface 71 intended to enter into directcontact with the disk DK. The friction shoe 22 also comprises a dovetailprofiled shape 6 which expands going away from the brake pad. Here, theprofiled shape is a dovetail profiled shape 6, which means that it has atrapezoidal shape section and is further complementary to a profile ofthe receiving slideway 4 of the shoe holder 3. Thus, the dovetailprofiled shape 6 is configured for being slid into the receivingslideway 4 of the shoe holder 3. Thus, the friction shoe 3 comprises asecond surface 72, opposite the first surface 71, which is in directcontact with the bottom of the shoe holder 3. It will further be notedthat according to the invention, the profiled shape can have aquadrilateral shaped section. More generally, the profiled shape canhave a section which has any kind of shape.

The dovetail profiled shape 6 comprises in the example shown alongitudinal groove 68 which extends the full length of the dovetailprofiled shape 6. The dovetail profiled shape 6 can be obtained from anextruded metal profiled shape cut to the needed length. The materialused can be stainless steel or a high performance aluminum alloy.

Further, as notably shown in FIG. 4, the friction shoe 22 comprises afirst member 1 and a second member 2 which each form one half of thefriction shoe 22. More generally, they at least have similar lengthsalong the longitudinal axis Z2. They are configured to be slid, oneafter the other, in the receiving slideway 4. They are thus juxtaposed,in contact with each other, in the tangential direction T, shown in FIG.5, of the disk DK as can be seen by superimposing FIGS. 1 and 5. Thecontact between the first 1 and second 2 members is made near a buttingzone which is, as shown in FIG. 4, a butting plane P.

Further, as shown in FIG. 5, the first member 1 comprises, at thelongitudinal end thereof facing the second member 2, a semicircularshaped recess 11 when it is seen from above and which extends over theentire thickness of the first member 1. Similarly, the second member 2comprises, at the longitudinal end thereof facing the first member 1, asemicircular shaped recess 12 whose dimensions are identical to those ofthe recess 11 of the first member. Thus, in the area of the buttingplane P between the first 1 and second 2 members, they leave a passageformed by the two recesses 11, 12 respectively of the first 1 and second2 members. This passage is arranged in an intermediate part of thebutting plane P, specifically in the middle along the transversedirection X. As shown in FIG. 3, this passage forms a pneumatic conduit9 which makes a fluid connection between a first space E1 which isdelimited by the surface 71 of the friction shoe 22 and a second spaceE2 which is delimited by the second surface 72 of the friction shoe 22.The through hole 38 provided in the shoe holder 3 is positioned oppositethe pneumatic conduit 9. The main axis A8 of the through hole 38 lies inthe butting plane P. More generally, the axis A8 of the through hole 38is coincident with the butting plane P or else separated, or at adistance, from the butting plane of less than 5 mm. Thus, the throughhole 38 and the pneumatic conduit 9 form a continuous pneumatic circuit.

The friction couple 16 also comprises a pneumatic junction ring 8 shownin particular in FIG. 6. The pneumatic junction ring 8 comprises aflange 81 which extends in an annulus transversely to the axis A8. Fromthe interior of this flange 81 extends a conical portion, which is herea cylindrical portion 82. It will be further noted that the portion canhave any kind of shape and in particular an arbitrary shape. Asindicated on FIG. 3, the pneumatic junction ring 8 is positioned in thepneumatic conduit 9 such that the flange 81 rests on the bottom of thereceiving slideway 4. The flange 81 is in direct contact with thesurface 72 of the friction shoe 22. The cylindrical portion 82 of thepneumatic junction ring 8 extends in the inner walls of the pneumaticconduit 9 formed by the recesses 11 and 12 of the first 1 and second 2members made without play, meaning without pneumatic leak. Further, asshown in FIG. 3, a height of the cylindrical portion 82 is equivalent toa height of the dovetail profiled shape 6 of the friction shoe 22. Itwill further be noted that the height of the cylindrical portion 82 isequivalent to a height of the longitudinal groove 68.

That way, the pneumatic junction ring 8 forms a pneumatic guide betweenthe through hole 38 of the shoe holder 3 and the pneumatic conduit 9 ofthe friction shoe 22. In fact, a large portion of the airflow enteringinto the pneumatic conduit 9 from the space E1 and directed verticallydownward is only able to reach the through hole 38. In fact, thepneumatic junction ring 8 limits leaks along the direction X in theinterstices located between the surface 72 of the friction shoe 22 andthe bottom of the receiving slideway 4 in direct contact with thesurface 72 and also by the longitudinal grooves 68 of the dovetailprofiled shape.

The friction couple 16 further comprises a first connector 42 arrangedinside the through hole 38 of the shoe holder 3. This first connector 42comprises a first member 44 attached to a second member 46. Thisattachment can in particular be an attachment by screwing or clipping.The first member 44 extends, by being away from the friction shoe 22,partially beyond the through hole 38, whereas the second member 46 isarranged in the through hole 38. The friction couple 16 also comprises aflexible hose 50 which is connected to the first connector 42. To dothis, the flexible hose 50 is connected to the first member 44 of thefirst connector 42. Thus, the flexible hose 50 extends away from thefriction shoe 22. It will also be noted that according to a variant, thefirst connector 42 can be formed as a single unit. In this case, thefirst member 44 and the second member 46 are jointly made.

In that way, the friction couple 16 comprises a pneumatic circuitcomprising the pneumatic conduit 9, the pneumatic junction ring 8, thefirst connector 42 and the flexible hose 50. The flexible hose 50 isadvantageously connected to a recovery tank for particles coming frombraking. Further, the friction couple 16 comprises a pump able to createa reduced pressure in the pneumatic circuit mentioned above and inparticular in the through hole 38 and a filtering element for trappingthe aspirated particles.

A recovery of the particles coming from braking of the railway rollingstock 10 is now going to be described.

When the railway disk brake system 12 is actuated, the actuator is urgedsuch that the brake pads 7 of the friction shoes 22 respectively of thetwo friction couples 16 enter into direct contact with the disk DK.Consequently, because of the friction between the disk DK which isrotating and the brake pad 7, particles coming from braking are releasedby the brake pads 7 into the space E1.

Simultaneously, a reduced pressure is created in the pneumatic circuitformed by the pneumatic conduit 9, the pneumatic junction ring 8, thefirst connector 42 and the flexible hose 50.

The reduced pressure can be created by a pump, for example a vacuumpump, or Venturi system near the braking system or at a distancetherefrom.

Thus, the particles coming from braking, initially in the space E1,reach the pneumatic conduit 9. Next, they reach the pneumatic junctionring 8, the first connector 42 and the flexible hose 50 for reaching thetank for recovery of braking particles. As previously indicated, thepneumatic junction ring 8 prevents braking particles from reaching theinterstices arranged between the surface 72 of the friction shoe 22 andthe bottom of the receiving slideway 4 in direct contact with thesurface 72. A significant quantity of particles coming from braking arethus recovered. The friction couple according to the invention istherefore less polluting.

Three other embodiments of the invention are now going to be describedwith the help of FIGS. 7 to 11. Only the differences from the firstembodiment are going to be covered explicitly. The numeric referencesfor identical objects remain unchanged.

According to the second embodiment shown in FIGS. 7 to 9, the dovetailprofile structure 6 of the brake pad 7 does not comprise thelongitudinal groove 68 shown in FIG. 3.

According to a third embodiment shown in FIG. 10, the friction shoe 22can be unitary.

A friction couple 16 according to a fourth embodiment of the inventionis shown in FIG. 11. The friction couple 16 comprises a pneumaticconnector 5 mounted on the first member 44 of the first connector 42.The positioning of the pneumatic connector 5 relative to the firstmember 44 is done by screwing or clipping. Thus, the pneumatic connector5 is mounted on the shoe holder 3 and extends away from the frictionshoe 7.

The pneumatic connector 5 is therefore pneumatically connected with boththe through hole 38 arranged in the shoe holder 3 and also the flexiblehose 50. The flexible hose 50 extends away from the friction shoe 22relative to the pneumatic connector 5. Further, the pneumatic connector5 is rotatable relative to the shoe holder 3 and to the friction shoe 22around the axis A8 which is, as indicated above, normal to the mainplane XY of the shoe holder 3 as shown by the arrow placed near thepneumatic connector 5.

Thus, the pneumatic connector 5 is more easily incorporated in thearchitecture of the railway rolling stock 10. In fact, it allowsorienting the flexible hose 50 relative to the axis A8.

It will be noted that the features of the various embodiments of theinvention can be combined, in so far as they are not mutuallyincompatible.

Further, many modifications can of course be made to the inventionwithout going out of the scope thereof.

Notably, the friction shoe 22 can comprise several members 1, 2. Forexample, the friction shoe 22 can comprise three or four members 1, 2.

Similarly, the shoe holder 3 can be non-unitary and comprise severaldistinct members.

The shoe holder 3 can comprise at least two through holes 38.

The invention claimed is:
 1. A friction set (16) for a railway diskbrake system (12) for railway rolling stock (10) with one or twodirections of movement (S1, S2) is provided where said friction set (16)comprises: a shoe holder (3) comprising a receiving slideway (4); afriction shoe (22) comprising a brake pad (7) and a profiled shape (6)configured for being slid into the receiving slideway (4), where thefriction shoe (22) comprises a pneumatic conduit (9) connecting a firstspace (E1) delimited by a first surface (71) of the friction shoe (22)to a second space (E2) delimited by a second opposite surface (72) ofthe friction shoe (22); - at least one through hole (38) arranged in theshoe holder (3) and laid out so as to be facing the pneumatic conduit(9); a pneumatic connector (5) mounted on the shoe holder (3),pneumatically connected with the through hole (38), extending away fromthe friction shoe (22) and rotationally mobile relative to the shoeholder (3), around an axis (A8) perpendicular to a main plane (XY) ofthe shoe holder (3); and a pneumatic junction ring (8) laid out in thepneumatic conduit (9) forming a pneumatic guide between the through hole(38) of the shoe holder (3) and the pneumatic conduit (9), wherein thepneumatic junction ring (8) comprises a flange (81) which extends in anannulus transversely to the axis (A8) of the through hole (38), and fromthe interior of the flange (81) extends a conical portion in inner wallsof the pneumatic conduit (9).
 2. The friction set (16) according toclaim 1 comprising a hose (50) pneumatically connected with thepneumatic connector (5) and extending away from the friction shoe (22).3. The friction set (16) according to claim 2 comprising a pump (P)connected to the hose (50) and configured for creating reduced pressurein the through hole (38).
 4. The friction set (16) according to claim 3,wherein the receiving slideway (4) of the shoe holder (3) is blind,specifically with one closed end (41) and one open end (40) forming anopening for the extraction and insertion of the friction shoe (22),where the friction set (16) further comprises a removable member forlocking (19) the friction shoe (22) in the receiving slideway (4). 5.The friction set (16) according to claim 3, wherein the friction shoe(22) comprises a first member (1) and a second member (2) configured forbeing slid in the receiving slideway (4) until contact of each other inan area of butting of the first (1) and second (2) members while leavinga passage therebetween so as to form the pneumatic conduit (9).
 6. Thefriction set (16) according to claim 3, wherein the friction shoe (22)is unitary.
 7. The friction set (16) according to claim 2, wherein thereceiving slideway (4) of the shoe holder (3) is blind, specificallywith one closed end (41) and one open end (40) forming an opening forthe extraction and insertion of the friction shoe (22), where thefriction set (16) further comprises a removable member for locking (19)the friction shoe (22) in the receiving slideway (4).
 8. The frictionset (16) according to claim 2, wherein the friction shoe (22) comprisesa first member (1) and a second member (2) configured for being slid inthe receiving slideway (4) until contact of each other in an area ofbutting of the first (1) and second (2) members while leaving a passagetherebetween so as to form the pneumatic conduit (9).
 9. The frictionset (16) according to claim 2, wherein the friction shoe (22) isunitary.
 10. The friction set (16) according to claim 1, wherein thereceiving slideway (4) of the shoe holder (3) is blind, specificallywith one closed end (41) and one open end (40) forming an opening forthe extraction and insertion of the friction shoe (22), where thefriction set (16) further comprises a removable member for locking (19)the friction shoe (22) in the receiving slideway (4).
 11. The frictionset (16) according to claim 10, wherein the friction shoe (22) comprisesa first member (1) and a second member (2) configured for being slid inthe receiving slideway (4) until contact of each other in an area ofbutting of the first (1) and second (2) members while leaving a passagetherebetween so as to form the pneumatic conduit (9).
 12. The frictionset (16) according to claim 10, wherein the friction shoe (22) isunitary.
 13. The friction set (16) according to claim 1, wherein thefriction shoe (22) comprises a first member (1) and a second member (2)configured for being slid in the receiving slideway (4) until contact ofeach other in an area of butting of the first (1) and second (2) memberswhile leaving a passage therebetween so as to form the pneumatic conduit(9).
 14. The friction set (16) according to claim 13, wherein the first(1) and second (2) members each form one half of the friction shoe (22).15. The friction set (16) according to claim 14, wherein the buttingarea is substantially defined as a butting plane (P), the first (1) andsecond (2) members have similar lengths in a longitudinal direction (Z2)of the shoe holder (3), and the through hole (38) has a center definingan axis (A8) coincident with the butting plane (P).
 16. The friction set(16) according to claim 13, wherein the butting area is substantiallydefined as a butting plane (P), the first (1) and second (2) membershave similar lengths in a longitudinal direction (Z2) of the shoe holder(3), and the through hole (38) has a center defining an axis (A8)coincident with the butting plane (P).
 17. The friction set (16)according to claim 1, wherein the friction shoe (22) is unitary.
 18. Arailway disk brake system (12) for railway rolling stock (10) with oneor two directions of movement (S1, S2) comprising a disk (DK) secured toan axle (14) or a wheel (18) and two friction sets (16) according toclaim 1 arranged on either side of the disk (DK).